PCB Files Format
PCB Files Format
For PCB Manufacturing or quotation , You need send us Gerber RS-274X files to check.
Below please find the instructions you’ll need for submitting your Gerber files to us for production of your printed circuit boards. If you need assistance, our customer service representatives can help you determine all of the file types you will need to submit for your PCB order.
Gerber File Format and ODB++ File Format
Gerber is an open ASCII vector format for printed circuit board design that shows parts of a board like copper layers, solder mask design, etc. Many applications can read this format because it simple, has detailed specifications, and has few bugs because of its wide use and subsequent debugging. The simple format of a Gerber means it is easy to identify and fix bugs as well.
There are three Gerber generations: Gerber X2 (current format), Extended Gerber, or RS-274X, and Standard Gerber, or RS-274-D, which is now obsolete. The Gerber X2 format contains layer stackup information, which was not in previous versions. Software that supports the X2 format will read and identify each item’s function in the file.
A RS-274X file contains the complete description of a PCB layer image without requiring any external files. It has all the imaging operators needed for a PCB image. Any aperture shape can be defined as well as positive and negative objects. Planes can be specified without the need to “paint” or “vector-fill” as in RS-274-D.
RS-274X is a complete, powerful and unambiguous standard to describe a PCB layer. It can be input and processed fully automatically. This makes it well suited for fast and secure data transfer and for reliable and automated workflows.
Remember to include the following when submitting Gerbers:
All copper layers (inner & outer)
Soldermask layers
Silkscreen/legend layers
Via plugging layers (if applicable)
Solder paste layers (for assembly)
Aperture list if apertures are not embedded in Gerber data
During the PCB layer assignment in our Auto File Verification, you will have to tell us which gerber file is which layer. This table will help you for some common packages.
Software: Eagle
| File Extension | Description |
|---|---|
| cmp | Top Copper |
| sol | Bottom Copper |
| stc | Top Soldermask |
| sts | Bottom Soldermask |
| plc | Top Silkscreen |
| pls | Bottom Silkscreen |
| drd | NC Drill |
Software: Orcad
| File Extension | Description |
|---|---|
| gtl | Top Copper |
| gbl | Bottom Copper |
| gts | Top Soldermask |
| gbs | Bottom Soldermask |
| gto | Top Silkscreen |
| gbo | Bottom Silkscreen |
| drl | NC Drill |
ODB++ File Format
There has been a lot of debate between whether Gerber format or ODB++ formats are better for PCB design. Some designers and shops prefer one format over the other. At Raypcb, we prefer ODB++ formats. Here’s a summary of both formats and their pros and cons.
ODB++ stands for Open Database and serves as a way to exchange data between computer-aided design (CAD) and computer-aided manufacturing (CAM) formats for circuit boards. This format was first introduced as ODB, and the “++” was added after a new version included components. ODB++ is an ASCII file that has all the information pertaining to the circuit board design.
Printed circuit boards are designed in CAD and transferred into CAM. CAD and CAM programs are usually made by different companies, so they need to agree on the type of data exchange. ODB++ is a manufacturing-oriented program. Many shops prefer this format for this reason because one file can consolidate all the information needed for the job, whereas some Gerbers need additional information from several files to make sense of the image layers. This eliminates the need to analyze each file to eliminate bugs.
| ODB++ | Gerber | ||
|---|---|---|---|
| Pros | Cons | Pros | Cons |
| One file includes stackup, layers, drilling, masking, net data | Different image format | Simple | Multiple files needed |
| Widely used | More complex format than Gerber | Widely used | Requires examination of all files at fabricator |
| Undergoes DFM / quality checks | Specification is precise | ||
| Easy to transfer to fabricator | Format supported by free viewers | ||
Introduction
Gerber files are the standard format used to transfer PCB design data from CAD software to PCB fabrication and assembly. Gerber files provide detailed information on copper layers, solder mask, drill data, etc. needed to manufacture a printed circuit board.
This article provides an in-depth overview of Gerber file format covering:
History and development
Gerber file types and purposes
Gerber file extensions
Gerber data format
Advantages of Gerber
Limitations of Gerber format
Gerber file generation
Manipulating and viewing Gerber data
Gerber validation tools
Best practices for Gerber file preparation
Understanding Gerber file format is critical for efficient data handoff and successful board fabrication.
History of Gerber File Format
Gerber file format was developed by Gerber Systems Corporation, pioneers in photoplotting and PCB imaging equipment.
1960s – Gerber introduced the first automated PCB plotter
1970s – Development of Gerber bar code standardized CAD data transfer
1980s – RS-274X Gerber file format released
1990s – Gerber Format becomes industry standard for PCB layout data
1998 – Revision RS-274X Rev D released
Today – Gerber remains predominant despite newer formats like ODB++
Types of Gerber Files
A complete set of Gerber files provides all data needed to assemble a PCB. Typical Gerber file types include:
Copper layers – Top, bottom, inner layers
Solder mask layer – Solder resist opening shapes
Silkscreen layer – Component legends and markings
Solder paste layer – Paste print template
Drill file – Hole sizes and locations
Profile file – Board outline and cutouts
Route file – Breakouts and scoring lines
Netlist file – Component pinouts and nets
Assembly drawings – Top/bottom assembly diagram
Gerber File Extensions
Standard Gerber file extensions help identify file types:
.GTL – Top layer copper
.GBL – Bottom layer copper
.GTS/GTP – Top solder mask
.GBS/GBP – Bottom solder mask
.GTO – Top silkscreen legend
.GBO – Bottom silkscreen legend
.TXT – Drill file
.GM1, .GM13 – Mechanical layer
.APR/.GKO – Aperture file
Gerber Data Format
Gerber data represents PCB images using vector photoplotter commands. Key elements:
Apertures
Geometric shapes – circle, rectangle, obround, etc.
Defines flash tool size and shape for photoplotting
Primitives
Graphics commands like line, arc, circle
Specifies image shapes using apertures
Coordinates
X and Y location
Positioning commands and interpolation
Polarity
Dark or clear polarity
Determines exposed or unexposed areas
Header
Defines units, coordinate format, etc.
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